1. Field of the Invention
The invention relates generally to a headlamp assembly for a motor vehicle. More specifically, the invention relates to a headlamp assembly having a movable reflector for adjusting the direction of a light beam emitted from the headlamp assembly.
2. Related Technology
Headlamp assemblies typically have a light source for emitting light rays, a reflector for directing the light rays in a forward direction as a light beam, and a housing for supporting the above components. In some constructions, a heat sink is connected to the light source for conducting heat away from the headlamp assembly. The reflector is positioned with respect to the light source that the light beam exits the headlamp assembly along a desired beam direction. More specifically, the desired beam direction is typically vertically aligned so that the light beam intersects the road at a point located a predetermined distance from the front of the motor vehicle is typically horizontally aligned so that the light beam shines generally parallel with the orientation of the motor vehicle or slightly laterally therefrom.
In order to initially achieve the desired beam direction, each headlamp assembly may require adjustment during installation into the motor vehicle. Furthermore, due to relatively continuous vibrations and/or other forces acting on the vehicle during operation, the headlamp assemblies may require periodic adjustment in order to maintain the desired beam direction.
Therefore, headlamp assemblies often include an adjustment mechanism for orienting the beam direction as desired. One such adjustment mechanism includes a plurality of adjustable-length connectors coupling the headlamp assembly housing to the vehicle frame. However, this design requires gaps between the headlamp assembly and the frame on several sides of the assembly so that the headlamp assembly is able to travel along the adjustment paths, thereby increasing the packaging space required for each headlamp assembly. Additionally, due to the relative size of each headlamp assembly, multiple adjustable-length connectors are required to effectively adjust the position of the headlamp assembly, thereby increasing the complexity and the part cost of the system and the likelihood that the connectors will become accidentally disconnected or severed.
Another adjustment mechanism includes a housing that is fixedly connected to the motor vehicle frame and a heatsink and/or light source movably coupled with the housing. This design, however, may cause premature wear on electrical connectors for the light source and/or cause the light source to become accidentally disconnected. Additionally, this design may require the electrical connectors to be longer than desired to permit the relative movement of the light source. Furthermore, the heat sink is typically a relatively large, bulky component and may be difficult and/or complicated to move with respect to the housing. This issue is especially troublesome in headlamp assemblies utilizing light emitting diodes (LEDs) because LEDs typically require more heat removal than other light sources, such as incandescent or fluorescent bulbs. Therefore, headlamp assemblies utilizing LEDs typically require relatively large heatsinks.
Headlamp assemblies are often able to alternate between a low beam mode and a high beam mode by moving one or more components of the headlamp assembly to alter the vertical orientation and/or intensity of the light beam. Switching between the two modes is typically accomplished via an actuation assembly that automatically moves one or more headlamp assembly components between first and second positions when the vehicle occupant toggles a switch within the vehicle interior compartment. However, these actuation assemblies are typically only able to move the components between a first position and a second position that result in drastically different beam angles and/or intensities. Therefore, this type of adjustment assembly is not conducive to making incremental adjustments of the beam angle.
Additionally, high/low beam mode actuation assemblies also typically include a plurality of components for moving the relevant components of the headlamp assembly in a relatively quick manner with a relatively low input force from the vehicle occupant. For example, the actuation assembly may include a plurality of gear ratios and/or a plurality of movable components interacting with each other to move the components of the headlamp assembly. These components add to the complexity and the part cost of the headlamp assembly. Furthermore, it may be undesirable for the headlamp assembly to be incrementally adjustable by a relatively low input force during beam orientation because such a configuration may cause inadvertent adjustment of the beam angle.
It is therefore desirous to provide a headlamp assembly that permits adjustment of the beam direction, while minimizing the size and complexity of the adjustment components, minimizing the number and size of the components to be moved during adjustment, and preventing inadvertent beam angle adjustment.